Shareholders of Coventry Health Care Inc. on Wednesday overwhelmingly approved acquisition by Aetna Inc. in a deal that is expected to close in the middle of next year.

Aetna announced in August that it will pay about $5.6 billion to acquire Coventry, of Bethesda, Md. Aetna is taking on Coventry's debt, bringing the total value of the deal to $7.3 billion.

Of the 104.94 million Coventry shares represented in the special shareholders' vote Wednesday, more than 99 percent of shareholders who voted approved the acquisition. Those voters represented 78 percent of all outstanding shares as of Oct. 15, according to RTTNews.com.

"We're pleased that Coventry's stockholders have overwhelmingly approved our proposed acquisition," Aetna Chairman and CEO Mark T. Bertolini said in a prepared statement. "We continue to believe that Coventry will complement Aetna's strategy to expand our core insurance business, increase our presence in the fast-growing Government sector and expand our relationships with providers in local geographies."

The transaction is subject to closing conditions, including the federal Hart-Scott-Rodino antitrust waiting period and approval by state insurance regulators, Aetna said.